Amalgam restorations have served dentistry for decades, but they often present clinical challenges such as overhangs, marginal leakage, and esthetic concerns. Replacing defective amalgam with composite resin not only restores function and esthetics but also provides an opportunity to refine proximal contact and contour.
This article presents a clinical case of amalgam replacement, emphasizing isolation techniques, wedge selection, and contour management in a tooth with a large interdental space.
Case Presentation
The patient presented with a defective amalgam restoration showing:
- Overhanged amalgam affecting the adjacent tooth.
- Large interdental space, complicating proximal sealing and contouring.
- Compromised esthetics and food impaction in the area.
These findings required careful planning of rubber dam placement and matrix/wedge selection before starting the restorative procedure.
Clinical Procedure
1. Isolation
Proper isolation was key due to the large interdental space. Rubber dam holes were punched strategically to ensure optimal adaptation.
2. Wedge Selection
The main challenge was achieving a tight seal while maintaining correct contour.
- Large wooden wedges provide good sealing but may compromise contour, leading to deficient proximal anatomy.
- Diamond wedges were selected because they expand horizontally without excessively increasing vertical height. This allows for:
- Effective sealing of the gingival margin.
- Preservation of correct contour and contact area.
- Reduced risk of overcontour or undercontour.
read this article about Complete Guide to Pre-wedging and Rubber Dam Isolation in Restorative Dentistry
A double seal technique was used to balance both sides of the proximal space. Buccal view evaluation ensured accurate contour adaptation.
3. Sectional Matrix and Ring Placement
Matrices were positioned back-to-back to recreate proximal walls. Sectional rings were applied, and special attention was paid to marginal ridge alignment.
4. Composite Build-Up and Finishing
Incremental composite placement was performed, followed by finishing and polishing. The marginal ridge level was carefully adjusted to maintain proper occlusion and anatomic form.
Discussion
This case highlights two key lessons in amalgam replacement:
- Large Interdental Spaces: These create a conflict between sealing and contouring. Diamond wedges provide an optimal solution by expanding horizontally without compromising contact point height.
- Marginal Ridge Control: Establishing correct ridge height is critical, as occlusal overload can destroy the anatomy achieved in the restoration.
By balancing seal and contour, the final restoration achieved both functional stability and esthetic improvement.
Conclusion
Replacing defective amalgam restorations demands careful planning. In cases with large interdental spaces, wedge selection becomes the cornerstone of success. Diamond wedges offer a predictable solution by maintaining seal and contour simultaneously.
Clinical Tip: Always evaluate contour from the buccal view and adjust the marginal ridge level before completing the restoration to ensure long-term stability.